|Pavinski Bitar, Paulina|
|Meinersmann, Richard - Rick|
Submitted to: Applied and Environmental Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/13/2010
Publication Date: 3/1/2010
Citation: Lang, P., Lefebure, T., Wang, W., Pavinski Bitar, P., Meinersmann, R.J., Kaya, K., Stanhope, M.J. 2010. Expanded MLST genotyping and comparative genomic hybridization evidence for host preferred groups in Campylobacter coli. Journal of Bacteriology. 76(6):1913-1925. Interpretive Summary: Campylobacter species are the most common bacterial cause of human diarrheal disease. Campylobacter jejuni is the most common in developed countries and C. coli causes a smaller but substantial disease burden. It is useful to study familial relationships, the so-called population structure, of bacteria to help determine routes of transmission that might lead to human exposure. For this study, the population structure of C. coli was defined with two methods of genetic typing, multi-locus sequence typing (MLST) and microarray comparative genomic hybridization (CGH) analysis. The MLST was a modification of a previously described method that added more gene sequences and is therefore more informative and this is the first time a CGH for C. coli has been described. With these techniques we were able to define specific groups of C. coli that associated with specific host animals and human samples most closely resembled the type from chickens and turkeys. It could also be seen that certain genes were actually more commonly associated with specific hosts, possibly indicating that there is transfer of genes between Campylobacter that makes more types efficient in attacking a variety of hosts.
Technical Abstract: The majority of previous work on campylobacteriosis has centered on the species Campylobacter jejuni, however, Campylobacter coli, the sister group to C. jejuni, is also a significant problem, but remains a much less studied organism. The purpose of this work was to develop and apply an expanded 16 locus MLST genotyping scheme to a large collection of C. coli isolates sampled from a range of host species, and to complete microarray comparative genomic hybridizations for these same strains, in order to: (1) determine whether host specific clones, genotypes, or clonal complexes are evident and (2) evaluate whether there are particular genes comprising the dispensable portion of the C. coli genome that are more commonly associated with certain host species. Genotyping and ClonalFrame analyses of the expanded MLST data suggest that (1) host preferred groups have tended to evolve in the diversification of C. coli, (2) this has happened repeatedly, at different times, throughout the evolutionary history of the species, and (3) recombination has played varying roles in the diversification of the different groups. Population genetic analyses using STRUCTURE suggest isolates from swine form a relatively homogeneous genetic group, chicken and human isolates show considerable genetic overlap, isolates from ducks and wild birds have similarity with environmental water samples and turkey isolates have a similar connection with human infection as do chickens. Concomitant with the information on evolutionary history derived from the MLST data, the microarray data suggests that a combination of common ancestry in some cases and lateral gene transfer in others are behind a tendency for sets of genes to be common to isolates derived from particular hosts.